SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '221f0943bbdaf07e67bfe69e5e94a0dfb5842e9870b570faa6cdcd9496668d4e' 
  AND token = 'sK7uyhzoyQPO+FqDHaoCUp+rquvPSVa3EhPhBaacoR0=' 
  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"
    }
  }
}