SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0b6d1c227b2e0fede173a38846b989d07b073d8b8b78bf188fc86b577182cb4' 
  AND token = '2S0dc9Iepkfp4pVe3YvjaObX9/vddXFq0BrMAzTlCk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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