SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47a3564c119dc171bfdc86948c4285771e373daebb39ed8977e07fb3249cdf6c' 
  AND token = 'Pd0u/x0ABcWbC9oGVgNBTEKV8YAPt7DrSKbavLMTX64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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