SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84a1a0eedfff0b30f62ec979f104f006efa204fb9369d22de5a5df9222379772' 
  AND token = 'aoW9/XLoQCLAoYJg+eloBW7O2Ynav5OdufFEjoWoM98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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