SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4df351feb7b5853655ba5998c9949f4e1e238f4be8125688eddf18fac65929d1' 
  AND token = 'ZaRYNFiGmlF8zlU0sD2eaRIXWsUYVWCZJQRQclKEdF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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