SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18cee8b34bb1d6fd16624df54ffefe73c42d2063b0458b658758c0b6f560c118' 
  AND token = 'WJkVfV6GZ4yjE+oChaPjVfIsVktfIyT3xdwYF+mX7uM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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