SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '162e9c34443714acbbc6bafea4c1d052907bdfa504c7dabd700ab7aff0f6e510' 
  AND token = 'ug1D5LGNknXcazY49eYGPHTmAO5CYCfbHiTV2NuskvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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