SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7309a30da8a74220d1147b79221370d2d45f09cbd2edca7b324d21d7a3d1926a' 
  AND token = '44dzbW/E6tP7M/kzyY7KO5vmO8fLrJYHI4rDVHDP8F4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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