SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99d6f5633f811842e648bbf50f0d2874ff27a533512dabb3fd9589a9275085d6' 
  AND token = 'Bt/J1XVyEghbAHceMIhbA6xTwZgsYa9oysLSYHzLIzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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