SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f37d71349a49f7d18ffbb7d628114e66fd43ad06d33657be89efb03be5763a6' 
  AND token = 'vHu5gV7nEJhLBlXPf1gWjKuu5xuKYnjbpPA9WYPkGR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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