SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87c7dc2328a82b2093ef85d510b82b8fe59ea345ac746e0b1b56e7ca2a692f62' 
  AND token = 'vJR9T/vcxVqzgshb0eF4+RQbcZwryhAyvofu/6YGtU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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