SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '974039077126e152e2404637659a5378d73fb4d81ce578fb65bea7d26f1f83d6' 
  AND token = 'CQIBrB/N+R6RmBuQzp8uMhxHpv1LPwfNVU1Wrus6sOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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