SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '578191549ae1f883325451253e1e2443c463069170f220f18450f37aac959a4f' 
  AND token = 'WGuQ5+Z/VdnfCmzgLDkK5M+J2XxKFiMTPyEcvIUa3pU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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