SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32bf2ce1be743275e2d2afc886c42b9db68dc900ad5ac058970183dfff24726f' 
  AND token = 'cG5rS3mTHuQYPNbFlJ70qvM7+EM24m6OYn02TkMvsP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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