SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c746c8d250c3c78fa15997ec3da815240aa6b7280eef7c8116e1dbe62ec53a11' 
  AND token = 'RaKnIqBo23AKHV4qyHrJ5JlZ1+gji9CmhF0poUikyx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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