SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '882016c0bf72e27766fb58006cdb031a8ae26016f0d74f8ac10c1ff8cde6ca49' 
  AND token = 'u3K1DJwPvYqlREFlYxibgCKHrhJ1lKClwWwy3PRs+38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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