SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fa29a1ab48c6ef0d168b893c29deb934a319b38988561004818a916c04a40a7' 
  AND token = '2uTWq3lFAD1yje/u1VC1R8McvSXLobdogYCiDhlHRmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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