SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8ac4a485aa0a79d833e4316a82591be247a00e7189c6df95ca273c9131dca9c' 
  AND token = 'RumvycpUqTYXzX1chQwi2zgFlTmLse1cO1ZHKnBsQq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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