SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9aeba71df901c55cf08403997d2a3e32badc8a37b9a5dfe45efee07f53945cd' 
  AND token = 'tj2R3O2nOW0T+/eNTpM0lcK7EecVXQkuPshc40SyAgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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