SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f54040b988d1ad2a588895ac06e2a5d7f6519447e8a0a30289a3305511fbe5ef' 
  AND token = 'vd+GhI8wtqHyFWMlSsvv/KFawwKlNFfOUwM+/guuLmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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