SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b417bca9defa39fb646a98fad06a319bd009c12dffb19a22076cd81fd0f8aa14' 
  AND token = 'DzKzNK59QqcpujHX0Avifbfu8TyM8fRdqEYztwPPkE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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