SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f71542ca37000157ed05d7dbc8fef1af3fc333710501f4de05f7984afecc9de8' 
  AND token = 'I5wfNtjUpgTDPsqpv/Np+09uzqbgA/FnDNqu2XIC4gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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