SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4e22a1680368c345506589b97bb0855c7f3c87084568e5276fb96f4109ba5ab' 
  AND token = 'V3vQBdG8wBmYwszIX1FEJ/GJJI2XT/H6sWitDJ35+pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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