SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70794db23f1b30870b3891e9cf79aa9a222d80e2cdabb664202201a0d137a7ad' 
  AND token = 'quchj5XJKUwYyDVFciLrbu2jG5TzxWsS1RDpT+8UwKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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