SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ce1416311ce40d26b39bb01cb7f69ff62e5d0f4ef1efb08ed1642f06026b471' 
  AND token = 'c97nLFxQIhFtiZ++EkfoKJqbfZvMuJbYIOWOETTgoMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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