SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '043507673c15fda5589ab260d19a0623791c46ef9e11cc86e1bd225998a5bb7d' 
  AND token = 'XfYHk3NphT3AUp/5AGZsH56v8i6qRRKc+6JpXsswPPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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