SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9ca355eef6ddb888db7d825d53e88678ebeb03acfe8f948a27e672917abfc7b2' 
  AND token = 'EqqZvzEV2ddS5SOTY6+VCp1yvhVXxwVGMQkPVceN9HA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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