SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bbc6e946f8664c3379bf31cb3142b792f688ebbbce7321e6c5b40d0efc6a143' 
  AND token = '+G2TiCxs9hOZsx804eoX5xVEMBX+LvfcKIFowAKCf/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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