SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a62c69a465160d60d3fbebe2baba869da59bf2a2deef8098104154f4cb1ae9d' 
  AND token = 'YUNE1Ugc40T/aSLpqOGd+FCOZP27egWq3Hnzj6nYu6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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