SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c34a2760fbca71fc565daf7c0bcee8003d4d5c053310390e8d490c3fafa4b07' 
  AND token = 'Qcj7NlUmtIrbMdl151gPnQgiriCtNmpM58qyu7agWlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}