SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44d44113c03880f71c8df20f4f768978941c8a755492d673dfd5fafe5b82a3c3' 
  AND token = 'TPTcTyS96HSTOFL7LbjBMz96m3uFKzY+lhqhoGu84fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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