SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b82f8543bcd7c4cf1bdf4afb1db9d98da7a557676d167cdb2caa27ea1a778585' 
  AND token = 'eUvJ4603iDy3qAJwCgFIalxd4VcCfsLOF/MBSEvXcJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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