SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59e5c7a02f2079a4669e88a2d863d85b8b5fea56491edd0d5d321ba2464a565f' 
  AND token = 'OzzThs7GJmeZJjuEPdY/qtVCOk+kchlVeq1t5xrzdX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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