SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32f7c5b8879433ce0ab3c724cc1927e5e4394a73ea498eafb4043566279210c6' 
  AND token = 'gICbFZG1uh/EdXwDnQ8sOlVSgPUBss8kDI7FnupYt/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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