SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4934bf4019271c6f8055f443babb2b14995f77731c3d3176bfe5623ab786a3a6' 
  AND token = 'yPTyv4w5UN/wTUkWV0f+tueBO0cyVZWP8YGRu++Bw7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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