SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a11ac2e7316c643a2b325d4fc3f7f966684114284e87ccbc9c88fe8269529e75' 
  AND token = 'is7G3qjVoJ7U15WD+j1MfGlO0lc+ddPyDGtCZv753yY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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