SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f3250e92c4cd86031eca9ee50fac39588219feac2c5e53024a842cbdabbacfc' 
  AND token = 'WMEox+GfiYJAp9+Ow7ws0Zi4HHp+QuUccj7FebvTPJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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