SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35c69ede83664c37fc065e1b0be1bb060127a8f3ea725741df5799abbe6b913d' 
  AND token = '9ZmIh/rpUxYXcRjwd4HQfxp1luG1YZFZCsF+MH4hFOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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