SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b537f60f533f7cbd8ccca02bfdbbf5a464bbe26139984c48d5e69cc4057b2e60' 
  AND token = 'cnOfOe7zI95vWREeL3HDxBzNp8VDMNbvXjc18gBJ1zM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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