SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e439840498c3adae33f1acfd6b180febe98a0262583ed37f15e6f7b263e413f7' 
  AND token = 'cvdyUF1Wc5vCVH4WR1EV44Ihc76xhCtl0iXNZmxeP7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}