SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd39f7af142726d458618a3fb46907e63d8aee114c7f0d94ce359e398e9452809' 
  AND token = 'Jv1to4NR5RuDEG+zhGHIcquV9L2+ohD6md9JS/01KLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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