SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33ec744800b9e3c2817dad93e4fb3855a24ddf13c78d079aadc24192c784a97c' 
  AND token = 'sEOPVhHZWOpNyQGVcnbkc8uPxwuhLDuSGe/+iGTdAko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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