SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9febb78f19da8186244b51d7c2f78c7a0db7b0e780e83655819bfb9c2db959d7' 
  AND token = 'oRoubafxOHqDfDpi4ZNw7GlZSESn3T3cVLnC92O5vt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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