SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12919d918683fb703a5ffeb4ea8b56edb1c984cda16f14186cde86335d05a742' 
  AND token = 'M2zffOiCkISWNFYVqVdzt+UCqRRIrRVGgyG9kN8cDZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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