SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2d6dfad12ab7382f92ca01b73f26e31b93d39c5817d6d0434a6106577e0cd98' 
  AND token = 'VVhwyaGOS74IljQFlH+SmY7/3wV3mkkZ/FsNAWdL/m8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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