SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad6613cd0be1bf64052358418c7effae13afabf8d74f2e2e737cbe83755319b2' 
  AND token = 'vsAe/zidvpKciMopO6mKtRIVPWg1ujl+je+yDO/H/Bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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