SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46190c69604f1855b8dc8e2868795d98df9128d4b5094890b2901a43db2d0f96' 
  AND token = 'hnuY7olUD+fJm/sV/iH5QrvBsBxeG9Hgu4HL5yi+hk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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