SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86d1817fe7bfa720944462662cb9b7d4be85de3d03113bef46ba3598819a4a8b' 
  AND token = 'N/0w+UkX6mJDLvrcrHSO5S4dn+8PQvlpZsihyTJPcK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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