SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c8cd8f4d00b57551d3883f37b0880d997381398f5a6c42de27a48bdc1ab62f' 
  AND token = 'lUdeIKFv7Dy+b2WyDzJ6iqj0Mp1tj7h/6vmOitSYsGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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