SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0acdb74c4e5454990194486efbad7f3711baff84d832ca98c23c530f3b0596dc' 
  AND token = 'P1/j1EpRxB8qx+Y8vg1Xh7aAyBixKtgrl23QTSbmuKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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