SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e6b9708c223831d20025f3dc6b6bafa537464279efe56d4898709141a2701d0' 
  AND token = 'TVsN2w1DxTI6NgeaX3zO7121frZZzBpfK4S6PXtPQ5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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