SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1977971180c9a5986d7d5f7b7f38d974b4a25eb5c6ae690bb12a4b57d34396ad' 
  AND token = 'qwmALJWjZ/6EBr412pjHbFZoEzVNX0Sj5A1SU5Y6v0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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