SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e970169229259ed6550319356fb9876f86d507a058d70db8cf07ee12b0d707b0' 
  AND token = 'QkwKpndq43q3JJBKpRtmhYpfAAGMGUiFHJExoHX5tvg=' 
  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"
    }
  }
}