SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58c50fb28fc6ef34b7121bebc47ac485940b9ab12c07555342491c6e406a0e4a' 
  AND token = 'p/zNS25qvoinZxyQdIjtx4/Jb5M62GRL4MXzeVcyzto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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