SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '884504453dc078a77b41c5c81daf9001ef12de030c62bffd8f710bfc29398617' 
  AND token = 'XudKiML2AMCdce/iQXAkVe1PrWoB3BYuqZ5xuJoFq5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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