SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8569ebb9a58f048668cc567db550f80df748a4e48c637bb448f1476f3d55f69b' 
  AND token = 'BrY4Scc91AIafHfmFISRfaH9kAgn8frIm7ASIM3AQ2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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