SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac2932758df67124f61a298f4bf4c9488e601e9cd2edba540f4fe024d74b67bd' 
  AND token = 'oKqlMNgaZ56hTLlMQpEeJdZ+DuJujGrSf4TwWnhv6Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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