SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78c129cd6ad101241b03c5c825433bcff6260cde2938ce63f3cfa83d12e461d1' 
  AND token = 'KRJbhEojL22WVPadPB1mgbBK3IOU4zWjdBhtmi6wFoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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