SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b25a3e01de6a255dd367b0a274e15245b574f006e8f0330397ef0705a1c1a9e0' 
  AND token = 'Iq5pZPFil0Z/PfRTPEpmSYLGD7ONxB5MfD+qNbhfj0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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