SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '620a696c15ce008fac45df912d60eedb1daf7de18b7858366a00e740915c885f' 
  AND token = '27gxahlX13Jhzp7YcgwmlyGWUZp7gMv9YxarJKHQ0yc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}