SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eeab16086f2bb24c833017487497a1eeb5ac18270dcadbef9b461fd9c513f91c' 
  AND token = 'OjhjSylCzwqAl2ruuKQgIe+cP64Md3hc5EgYVRa+pfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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