SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eadfb80067d6ab7095c2180883a303cfe641e73a044871fe3b821463186dd7af' 
  AND token = 'JTiW8gSxVeSBc6bIA0+c291FEenbAqSDKkM24c7PO34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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