SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec3af54ef52cc5c401e6188387f28613a45793058543340e72c043adaa95c2a2' 
  AND token = 'YV+3Tfo5kdGfXDEJqh1jG1CzM+3NZxP4LcpY+C6ybLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}