SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca3a4b9946b715291cac0aae58b6e96fd1ce188da4d2a2b52e65d14e57e6f93a' 
  AND token = 'rQJiKRoNLGMX7i+yRCqWvw9vzVlu/24bugrRqtH2nnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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