SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97c1d9dfe32f32280cf52b27778cdda8036a9991e50328a391540b3f26f82de4' 
  AND token = 'x/YUD/OGqb1N0xlCrFcrlFFOprlDrYTSGNNl+FegXzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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