SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a22c19abb5aa99875c362c501f6a77f17876df09894e0f071b056ff1fc1541ad' 
  AND token = '0eJ76535eH1p9tutqIxlspYH9cOuOsqSeUosK0FXWvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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