SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '81e7b103c947969fbbcda1c6202ac69008f8144d59a23ccbec39355774454e30' 
  AND token = 'Bue07nKRW8++yJj7T2spzBUQuS41dWu9rdm6x9dw1+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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