SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fd854d25aa9398fb1d57175f20e3255f4ffe0f4d3013e0d7833dbc5dd916969' 
  AND token = 'nx/wT3uF5MvaT66CeuLY0l/WQLC9bxpYheVACUWmp+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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