SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f3ae627f45534b78ebd1c304a448c7e0ef413ed31dbd04c55274f502b939ef5' 
  AND token = '4lmDKnDnBMa1ShKucPu8Xj9zl+of7xi08+tW8Vxtf5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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