SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4365bc9bceec606fb79d18771d661d2294ebb18dd55f8bba22f9fc81d007cec' 
  AND token = 'M5NaHwu/pLM8oImVAd11dAVHBPQuPGLoGgukUru/tqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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