SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9448b8961f5a0013864ea08210165417322ec5a44c86965bef36acf4251ca1e9' 
  AND token = '+T5+UhosKzqPjrbE64Cq990AnjQ7r+z3yiEWWO5k91Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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