SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8670a79a774b3eefd4211c30eca1a3a8597e92bf48a93ce6381346bde0de381' 
  AND token = 'AZ7y1qCdEuOVeyyX0Ppoie+QIaXL+wy0SfApM+D7zjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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