SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '385898f0be10ca0bc0d673e21287cf20555befebd854d2cc37c50e76c7f6764c' 
  AND token = '9QpprkJqPKqJ2l4z/BTzbfAwKipCOGHdo98dYdqYRvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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