SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8f37dd51d41edbddacc7fc2fdc0402a0891dfb580ab16827de87e953f19816bd' 
  AND token = '/JVScjKrhYmOX0FEdxvATSLJ0hnpr5kA4IYYaHqfUxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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