SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5505ad98fc3f4ec5706aa9f398642628afa0b647dece16f39a4f829f045dda98' 
  AND token = 'Ww4kf2GEXMVop4HcmaGiIWWL48sAMInOV8Lnvdw2bqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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