SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5107fc8ca31322631f716e6912356a50497cab9a25f71ab5cfe9a7f372485ec8' 
  AND token = 'OCEeSJgdw8kqi+Aci/zMRm6L589DGyPBO6cQFu2ev68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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