SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a018b3ebaccf913d774745eda3cd9bb60ad3649291ecf3c2b0cdc8edfed4522' 
  AND token = 'BlaBvbDLMDzykzAkIvUQ9bF/jmYts5GtuIsyw8wGzKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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