SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7f6fb3bb8c1d523aa0d6de0fef2e5cacfc211fcfcf5aa73d54c9ff4a425fa5a' 
  AND token = 'CxYo9yijyP9NbhZR3ShkhcO9fX8tgW9iUSlNRz8OWkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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