SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f83f25037236bb4cf4eaf8f5cf32a4d54bc269bb41ed962637b231e6b583486' 
  AND token = 'p/m1qKtOS0gQb+suaryfISEWWxh1a+iW+ZXGrPi/J9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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