SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aac658ce6daa73f063285a1fedde55112f1e5d9f66fb1d71894fc4a71f4c8d67' 
  AND token = 'h8K65HYpKJjomcObh8WPpBts6IdoPUKZ/Pf9B+zMMqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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