SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec29084d7b178ca8d44470b428bb4d839a9db62030be005cdf495a2f7815b365' 
  AND token = 'U9+6hiQvBBq87iGkmwyvk/dSD+tnQv71UwqaGCYQOZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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