SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26e682136107bd027de3d00561acc2dcbe7d4e02631e537b3629b39fc480d93a' 
  AND token = 'tO2ZjJCK1UrQ+XQEUtd/JtlahoAXiZRHYZMMAA3Ixng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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