SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bf3f75628bb4a2300bc4358e3bf80b74eb77c0609bdd4715e23514b57ea604d' 
  AND token = 'rtMbSl69uJX2xNSpdD6aJ3GH2A/ReSgjiqRW7olfHOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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