SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e18039afcc9c31c7e98ac318f7d75f94af85d277bd7f07809c9c659082297924' 
  AND token = 'V9gEJHGIdgmdyIqvEXG2ab2q/GaBaRD/GnawITpJ0oQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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