SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06cd869d0f856294514c2d278659cdadee4364db296b7d998713cf496a168215' 
  AND token = 'vMwAsPmbCetx2DiKk6qqGEL+kaXmEuekqQ2OiVU7gVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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