SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70170ebe9fbdd6dba08177d1ec0775fb81df4fe4e28b6bbae81458d1b2c99191' 
  AND token = 'AcGoxVxVRC2BAqCyy5y9T1lF+5z30tWxaDuuXS2ydJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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