SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96f79d868c8f1981ab91929ec0556663311e72a007c56933769b7b6e09a6c905' 
  AND token = 'CQGVi/zORiLDUfcLVlDskZqyQc0wkMiMMTJW1+pzuDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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