SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0443459939b41980b8a8b75bb9f1592078989adb25c6427d7843833df6e5e268' 
  AND token = '7cCc/voNUxtPrutChFBdDgbMOHYe78D02fp6R/CLZvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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