SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed12db999676ec4db9150c47a7df58ac23768bb13a12df922a9844636db8bb21' 
  AND token = 'KVh9NhjJoJ2021w2GGCFXsAvWrSHqBFjc6fx6DLNEw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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