SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f965fbb3df25394790c70a9c15c12de87620ae7d9d35dbf8a07f2b5d42718025' 
  AND token = 'SRn7k+YxdFTh/GqAUIu62JgIFKQ3+eYy1Mhlb6Uaj4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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