SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aefcad8f797ad486696e2d72088f24f77bee5ef4cf201936266b36e037e0a6a6' 
  AND token = '0ESItXljDQXzhj51yyCsrRkFbkGwd0Yo3rGr9kQEdTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}