SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f9f1e3492eca12e6dcd522744727041ab18e21d1085df9693151a2886f7c9a8' 
  AND token = 'vEN3G8JKQJEkrF4BR0PdWgiWVPbYT2MZyInlVxqgkEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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