SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a0b0138d5118db066245d0f14c675f1bdfe75ae6af0d400aa20dd7914968e0a' 
  AND token = 'Y6pCB1pCkZpKvizvnPI/nqJjvPnL9p2nAZg7TS53XhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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