SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575bb2b14c4fb58180941157ed18f8d90689075a74af08221ceb7b6440273d1b' 
  AND token = 'zCh+2s4/3Z/x589tzsRY7HZjLw+qTCTn9n2oB/+jctw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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