SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5856d349c17aef1889301818a707e1aac4246ee9583876faba3fc988259ba09' 
  AND token = 'DgFueRGoSPMeuX0vfZJtsgMSF2aw/j4EoRSlWfTOg3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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